The present invention relates to an electrical plug-in contact, in particular a test adapter, as claimed in the preamble of claim 1, and to a system having an electrical plug-in contact as claimed in claim 11.
An electrical plug-in contact of this kind has already been known for a long time. The known electrical plug-in contact, which is in the form of a test adapter, has a first region for making electrical contact with a meter and has a second region for making electrical contact with an electrical conductor, with the longitudinal axes of the two regions running laterally offset and parallel in relation to one another. In this case, the first region is formed in the manner of a sleeve and the second region consists of three sheet metal strips which are riveted to one another. The first and the second region are soldered to one another and encapsulated with an insulation material, in particular plastic.
The present invention is based on the problem of specifying an electrical plug-in contact which is simpler in terms of design and more reliable in terms of application.
This problem is solved by an electrical plug-in contact having the features of claim 1. The dependent claims relate to advantageous developments of the invention.
A significant advantage of the electrical plug-in contact according to the invention is, in particular, that it is simple in terms of design and reliable in terms of application. The electrical plug-in contact according to the invention can therefore be produced more simply, and is consequently more cost-effective. On account of the special structural design of the plug-in sleeve of the electrical plug-in contact, the plug-in sleeve bears against the electrical conductor over a large surface area and therefore ensures good electrical contact between the electrical plug-in contact and the electrical conductor.
Although U.S. Pat. No. 2,980,883 already discloses equipping an electrical plug-in connector with an elongate hole in the region in which said electrical plug-in connector makes contact with an electrical conductor, the known plug-in connector does not exhibit the combination according to the invention of an elongate hole and a longitudinal slot which is situated diametrically opposite said elongate hole.
However, it is specifically this combination which advantageously leads to the plug-in contact according to the invention being uniformly cushioned when it is moved to the plugged-in position. The elongate hole and the longitudinal slot ensure symmetrical force absorption. The plug-in sleeve can deform elastically over a large area. As a result, the plug-in sleeve bears in an effective manner against the electrical conductor when the electrical plug-in contact is in the plugged-in position, and therefore a good electrically conductive connection is established, without the electrical plug-in contact being plastically, that is to say permanently, deformed in the process.
Furthermore, the production of the known plug-in connector is complicated and therefore cost-intensive. The known plug-in connector is not suitable for use as a test adapter either.
A further plug-in connector is known from DE 295 16 504 U1. The known plug-in connector has a pin contact connection and a corresponding socket connection. In this case, only the socket connection has two diametrically opposite longitudinal slots in the region in which contact is made between the pin contact connection and the socket connection. However, the manner of operation of the known socket connection is naturally fundamentally different from that of the electrical plug-in contact according to the invention. While the known socket connection has to expand when the pin contact connection is plugged in, the plug-in sleeve should compress in an elastic manner when the electrical plug-in contact according to the invention is moved to its plugged-in position.
The type, dimensioning and material of the electrical plug-in contact can be selected within wide suitable limits. The plug-in sleeve and/or the first region are/is advantageously cylindrical. The production of the plug-in sleeve is simplified in this way.
In principle, the dimensioning of the elongate hole and the arrangement of said elongate hole on the plug-in sleeve can be freely selected within wide suitable limits. The elongate hole expediently has an extension in the longitudinal axis direction of the plug-in sleeve of at least 3 times the extension of the plug-in sleeve perpendicular to the longitudinal axis.
An advantageous development makes provision for the longitudinal axes of the two regions to run laterally offset and parallel in relation to one another. As a result, it is possible to position a plurality of electrical plug-in contacts, in particular test adapters, in an extremely narrow space without the electrical connection, for example of a meter, to the first region of the respective electrical plug-in contact being made difficult in the process.
A particularly advantageous development of the electrical plug-in contact makes provision for the plug-in sleeve to have at least one latching recess or a latching hole laterally offset in relation to the elongate hole, said latching recess or latching hole being formed in such a way that the electrical plug-in contact, when it is in the plugged-in position, is latched to the electrical conductor. This ensures that the electrical conductor makes reliable contact with the electrical plug-in contact when the electrical plug-in contact is in the plugged-in position.
In principle, it is possible to provide just one single latching recess or one single latching hole on the latching sleeve. The latching recess or the latching hole is advantageously in the form of a pair, with the latching recesses or latching holes being situated diametrically opposite and being arranged perpendicular to the elongate hole and the longitudinal slot. In this way, the plug-in sleeve is not subject to mechanical loading on one side and there are no undesirable relative movements between the plug-in sleeve and the electrical conductor when the electrical plug-in contact is in the plugged-in position.
A particularly advantageous development of the two abovementioned embodiments makes provision for the elongate hole to have an, in particular symmetrical, constriction, which extends transverse to the longitudinal axis of the plug-in sleeve, in the region of the latching recess or of the latching hole. This ensures that the plug-in sleeve has enough material in the region of the latching recess or of the latching hole in order to allow for elastic deformation of the plug-in sleeve. Otherwise, insufficient material would undesirably lead to plastic deformation of the plug-in sleeve in the region of the elongate hole.
An advantageous development also makes provision for the elongate hole to have an extension perpendicular to the longitudinal axis of at least 40% of the plug-in sleeve in the regions without the constriction and, in the case of the abovementioned embodiment, of at least 25% of the plug-in sleeve in the regions with the constriction. Elastic deformation of the plug-in sleeve over a wide range is possible in this way.
A particularly advantageous development makes provision for the plug-in sleeve to have a run-on slope at its free end. As a result, the force which is to be applied for moving the electrical plug-in contact to its plugged-in position is reduced.
An advantageous development makes provision for the first region and the second region to be integrally formed. The production of the electrical test adapter according to the invention is further simplified in this way since a joining process for mechanically connecting the first region to the second region is dispensed with.
A further particularly advantageous development makes provision for the plug-in sleeve and/or the first region to be in the form of a rolled sheet metal part. The production of the plug-in sleeve and/or of the first region is further simplified as a result.
The invention also relates to a system comprising an electrical plug-in contact as claimed in one of the preceding claims and comprising an electrical conductor, in particular a current bar.
In principle, the design and the relative arrangement of the electrical plug-in contact and the electrical conductor in relation to one another can be freely selected within wide suitable limits.
A particularly advantageous development of the system makes provision for a polygonal, in particular square, hole for accommodating the, in particular cylindrical, plug-in sleeve when said plug-in sleeve is in its plugged-in position to be formed in the electrical conductor. This ensures reliable contact is made between the electrical plug-in contact and the electrical conductor; this is particularly true in the case of electrical plug-in contacts in which the electrical plug-in contact and the electrical conductor are latched by means of the latching recesses or latching holes which are formed on the plug-in contact.
An advantageous development of the system makes provision for the dimensions of the elongate hole and those of the electrical conductor to be matched to one another in such a way that the elongate hole projects beyond both sides of the electrical conductor in the longitudinal axis direction of the plug-in sleeve when the plug-in contact is in the plugged-in position. This ensures that the electrical plug-in contact makes reliable contact with the electrical conductor.
A further advantageous development of the system makes provision for the dimensions of the latching recess or of the latching hole in the direction of the longitudinal axis and those of the electrical conductor to be matched to one another in such a way that there is play between the plug-in sleeve and the electrical conductor in the longitudinal axis direction of the plug-in sleeve when the electrical plug-in contact is in the plugged-in position. Manufacturing and production tolerances can be compensated for in this way. Furthermore, the play ensures that the electrical contact is made between the electrical plug-in contact and the electrical conductor in a desired manner by means of the electrical contact areas provided for this purpose, and not by means of the boundary areas of the latching recesses or latching holes.
As a result, it is also possible to make contact with a series of electrical conductors, in particular current bars, with different strengths and positions with a single type of electrical plug-in contact. Therefore, the variety of components is reduced in a desirable manner.
A further advantageous development of the system makes provision for the edge length of the polygonal hole to be 80% to 97% of the extension of the plug-in sleeve perpendicular to the longitudinal axis of said plug-in sleeve. As a result, the mechanical contact between the electrical plug-in contact and the electrical conductor is ensured without departing from the elastic deformation region of the plug-in sleeve.